Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing several insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various layers using lithography to form circuit components and elements thereon.
There is a trend in the semiconductor industry towards reducing the size of features, e.g., the circuits, elements, conductive lines, vias, and contacts of semiconductor devices, in order to improve the performance of the semiconductor devices, reduce power consumption, and meet smaller packaging requirements, for example. However, as feature sizes and packaging of semiconductor devices are reduced, overheating can become a problem, which may deleteriously affect device performance and cause device failures.
Heatsink structures may be attached to packaging for heat dissipation of integrated circuits. Another approach is to form micro-channels or grooves onto a back side of an integrated circuit, after processing the front side of the integrated circuit. One approach is to form the micro-channels and cover them by a Pyrex™ by Corning Glass Works cover plate. Another approach is to fill the micro-channels with a decomposable polymer, cover the polymer with a first permeable overcoat, and after decomposing the polymer, form a second non-permeable overcoat over the first permeable overcoat.
However, the second micro-channel approach requires a complex manufacturing process flow. Furthermore, known micro-channel approaches are required to be performed after front side wafer processing and with a standard wafer thickness, because of warping of thinned wafers and handling difficulties. Die yields can be reduced, and there are limits on temperature budgets, due to the finalized front side processing. There are also limits in applications requiring extremely thinned dies, such as in 3D integrated circuit stacking. A significant spatial distance from active devices is also required, because of etch non-uniformities during micro-channel or groove etching into the silicon substrate from the wafer backside.
Thus, what are needed in the art are improved methods of cooling semiconductor devices and structures thereof.